Heretofore, reinforced rubber articles such as giant tires having an opening therein have been repaired utilizing an uncured patch. Generally, the tire was taken to a retread or rubber repair shop where the damaged area was removed. Generally, an all-purpose gum rubber was applied to the opening. On the interior side of the article, the general area of the opening was buffed and a conventional rubber cement applied thereto. Then, an uncured patch was applied. The gum rubber as well as the adhesive was then cured in a mold by applying heat thereto or through utilizing steam heat for a period of approximately 8 to 12 hours.
Prior art patches fall into two classes, the chemical cure patches which are high in cost and provide only poor adhesion to the substrate and uncured patches which require the use of heat for proper cure and adhesion. Unlike the method of heat application for the gum rubber filler, a rather sophisticated process must be used to cure this latter type of patch, to wit, a tire mold or similar device. Thus when a patch is required, an on-the-spot or in situ repair is exceedingly cumbersome at best and in most cases impossible, requiring the article to be returned to a repair shop.
The present invention utilizes a cured rubber patch secured to the elastomer substrate through an adhesive system which is curable at ambient temperatures. There is therefore no need for the use of a tire mold to effect repair and the article can easily and quickly be treated in the field, saving both time and expense. The adhesive system utilizes an amine curable polyurethane or other prepolymer and a treating agent.
Considering the prior art, U.S. Pat. Nos. 3,755,261 to VanGulick; 3,888,831 to Kogan; 3,834,934 to Broisman; 3,644,256 also to Broisman; and 3,718,587 to Bhakuni relate to amine curable curing agents, amine curable polymers, or R.F.L. type adhesives. However, these patents lack any suggestion of applicants' internal cavity, treating agent or repair of an elastomer article.
U.S. Pat. No. 3,779,794 to DeSantis relates to a moisture-curable polyurethane sealant primer system, whereas U.S. Pat. No. 4,085,283 to DenOtter relates to frame retardants utilized in cyanuric acid derivatives. Hughson Chemical Division, Lord Corporation, Product No PS-2682-71 relates to a surface primer for elastomeric substances utilizing a proprietary compound thought to be mono- or di-chloroisocyanuric acid. An article entitled "Room Temperature Vulcanizing Adhesive Based on Ethylene-Propylene-Diene Terpolymer," Cantor, Uniroyal, Paper No. 18, presented to the Division of Rubber Chemistry of the American Chemical Society, Denver, Colo., Oct. 10, 1973 refers to various oxidants which effect ambient temperature cures of E.P.D.M.
U.S. Pat. No. 4,136,219 to Odam relates to a polyurethane paint which is applied to vulcanized rubbers. British Pat. No. 1,352,645 relates to a polyurethane paint which is applied to vulcanized rubbers.
U.S. Pat. No. 4,125,522 to Becker relates to a polyurethane adhesive, whereas U.S. Pat. No. 3,966,530 to Cutts relates to triazoline diones which are utilized in lieu of chlorinated or halogenated donors for treating elastomeric surfaces to improve adhesion.
U.S. Pat. No. 3,143,156 relates to utilizing a non-fully cured plug to repair an aperture.
U.S. Pat. No. 4,143,454 to Utsonomiya relates to a method of attaching connecting parts of an offshore structure wherein a liquid rubber is applied over a treating solution which may contain a halogen molecule. As such, this reference lacks applicants' treating agent as well as repair of an elastomeric article having a patch thereon.
U.S. Pat. No. 4,158,378 to Pearson relates to a cured rubber tire having a specific polyurethane therein and to a chlorine water treatment. Hence, Pearson also fails to teach or suggest applicants' recited treating agent as well as the patched article.
U.S. Pat. No. 3,991,255 to Blaskjiewicz relates to the adhesion of a polyurethane to an EPDM surface utilizing various adhesives, however Blaskjiewicz does not use his treating agent to form a treating layer and utilizes elevated temperatures.
U.S. Pat. No. 4,300,970 to Honda does not disclose amine curable resins or an ambient temperature cure.
U.S. Pat. No. 4,240,852 to Gomberg relates only to the use of a cyanoacrylate adhesive.
U.S. Pat. No. 4,352,704 to Williams relates to applying tire tread to a tire. This patent lacks any suggestion of applicants' treating agent or the repair of a tire aperture.
U.S. Pat. Nos. 4,327,138 and 4,399,852 to Hausch fail to disclose a cured rubber patch in repairing a rubber article. Similarly U.S. Pat. Nos. 4,401,145 and 4,311,181 also to Hausch relate to an indicia and not to any cured patch.
U.S. Pat. Nos. 4,434,832 to Koch and Barbin and 4,485,135 to Koch relate to ambient temperature cure of elastomers having a hollow therein as well as a patch.
U.S. Pat. Nos. 4,465,535 to Koch, Fieldhouse and Oziomek relates to the use of a specific solvent, 1,4-dichloro-ethane, utilized in connection with a treating agent.
One prior art method of repairing a tire article relates to the utilization of a proprietary compound thought to be a mixture of rubber and accelerators which is applied to the aperture and then cured. In general, a very poor adhesion results and heat is required.
However, none of the above patents, methods, etc. relate to the creation of an interior cavity in a damaged area which cavity is filled with a filler, covered with a cured patch and adhered thereto with an ambient temperature curable amine curing agent.